Editing Talk:Build from source

==Manual Introduction==

Below is some proposed text for the manual for collaborative editing:

-----------------

Building Octave is easiest on Unix-like systems, e.g. Debian, Ubuntu,
etc. The procedure for building and installing Octave from its sources
on a Unix-like system is described in the sections below. To build on
other systems requires considerably more expertise, but is possible.
Further information on this is available online, such as on the Octave
wiki (http://www.octave.org/wiki/index.php?title=GNU_Octave_Wiki), but
note that this information is not directly controlled by the Octave authors.

Octave is a large and complex program which depends on many other
packages and libraries. The first section below describes how to obtain
and install these dependencies before attempting to build Octave itself.

This second section describes the process of building Octave itself. On
a Unix-like system building Octave can often be as simple as running a
few commands from the terminal. The Octave build system is based on GNU
make (http://www.gnu.org/software/make/). This is a commonly used system
for compiling large and complex programs. It is often supplied as a
standard package, so you are likely to already have it installed. Before
running make to build Octave you must also first configure the build
process on your system by running a shell script supplied with the
source code. This configuration stage is also described in the second
section.

Note that this description applies only to Octave releases. If you wish
to build the development source, you must obtain them from the Mercurial
archive. Building the development sources requires additional steps as
described in <Building the Development Sources>. Further information on
building Octave can be found in the readme files supplied with the
source code.


==New page content==
Here I'm working on a new version of this page [[User:Rettaw|Rettaw]] 04:49, 14 June 2013 (PDT)

----

===Clone the sources===

The latest development sources of Octave are available via this [http://www.octave.org/hg/octave Mercurial archive]. With Mercurial and git installed you get the latest development version of Octave sources with the following command: 

 hg clone http://www.octave.org/hg/octave 

This will clone two repositories, one of which is subrepository of the main Octave repository. Once you have these, you can resync with the archive by doing 

 hg -v pull 
 hg -v update

The -v option is not required but provides extra information about what was pulled and updated. 

If you decide to use the development sources from the Mercurial archive, please read the file [http://hg.savannah.gnu.org/hgweb/octave/file/tip/etc/HACKING etc/HACKING] that is available with the source files. 

====Build tools====
The following is lifted from the manual ([http://www.gnu.org/software/octave/doc/interpreter/Build-Tools.html G.1.2]) and [http://hg.savannah.gnu.org/hgweb/octave/file/tip/etc/HACKING etc/HACKING] the '''2013-06-14''', if the current date is much different and your build fails because of missing requirements, please follow the links and see if they have been updated.

The following tools are required: 

{| class="wikitable"
|'''C++, C, and Fortran compilers'''|| The Octave sources are primarily written in C++, but some portions are also written in C and Fortran. The Octave sources are intended to be portable. Recent versions of the GNU compiler collection (GCC) should work (http://gcc.gnu.org). If you use GCC, you should avoid mixing versions. For example, be sure that you are not using the obsolete g77 Fortran compiler with modern versions of gcc and g++. 
|-
|'''GNU Make'''||Tool for building software (http://www.gnu.org/software/make). Octave's build system requires GNU Make. Other versions of Make will not work. Fortunately, GNU Make is highly portable and easy to install. 
|-
|'''AWK, sed, and other Unix utilities'''||Basic Unix system utilities are required for building Octave. All will be available with any modern Unix system and also on Windows with either Cygwin or MinGW and MSYS. 
|}

Additionally, the following tools may be needed: 

{| class="wikitable"
|'''Bison'''||Parser generator (http://www.gnu.org/software/bison). You will need Bison if you modify the oct-parse.yy source file or if you delete the files that are generated from it. 
|-
|'''Flex'''||Lexer analyzer (http://www.gnu.org/software/flex). You will need Flex if you modify the lex.ll source file or if you delete the files that are generated from it. 
|-
|'''Autoconf'''||Package for software configuration (http://www.gnu.org/software/autoconf). Autoconf is required if you modify Octave's configure.ac file or other files that it requires. 
|-
|'''Automake'''||Package for Makefile generation (http://www.gnu.org/software/automake). Automake is required if you modify Octave's Makefile.am files or other files that they depend on. 
|-
|'''Libtool'''||Package for building software libraries (http://www.gnu.org/software/libtool). Libtool is required by Automake.
|-
|'''Gnulib'''||<http://www.gnu.org/software/gnulib/>
|-
|'''gperf'''||<http://www.gnu.org/software/gperf/>
|-
|'''Gzip'''||<http://www.gnu.org/software/gzip/>
|-
|'''Mercurial'''||<http://mercurial.selenic.com/>
|-
|'''Perl'''||<http://www.cpan.org/>
|-
|'''Rsync'''||<http://samba.anu.edu.au/rsync/>
|-
|'''Tar'''||<http://www.gnu.org/software/tar/>
|}

===Run the bootstrap script===
The following are abridged instructiongs from etc/HACKING.

After cloning Octave, you will need to run the bootstrap script:

 $ ./bootstrap

Running this script will result in the createion of the configure script. 
The bootstrap script comes from gnulib, but is kept in the Octave source archive. 
It should be updated from the gnulib sources as necessary.

If you have a copy of gnulib in some directory apart from the Octave
source tree, then pass the name of the directory containing gnulib-tool
to the bootstrap script using the option: 

 --gnulib-srcdir=DIRNAME

Additional options besides --gnulib-srcdir can be passed to bootstrap and
they will be forwarded without modification to the gnulib bootstrap script.

Once the bootstrap script completes successfully, you may configure and
build Octave.

===Configure the build===
It is very recommended that you build Octave in a separate directory tree from the sources.  
For convenience we recommend a subdirectory to the main octave directory.
For example, after you finished running the bootstrap script (takes a few secondds), run the
following commands to create a build tree, configure, and build Octave:

 $ mkdir octave_build_directory
 $ cd octave_build_directory
 $ ../configure

Running configure will take about half a minute. After it's finished, and if you are satisfied with
the result, just run make

 $ make

Building octave will take something on the scale of hours, 
the exact ammount depending on if the programmers or cpu engineers are ahead in the eternal race of performance versus cruft. 
The best thing to do is to leave it over lunch, or possibly overnight if it's late. You probably should sleep more anyway Jonathan.

====Build dependencies====
The [http://www.gnu.org/software/octave/doc/interpreter/External-Packages.html manual] lists the following as required packages:

{| class="wikitable"
|'''BLAS'''|| Basic Linear Algebra Subroutine library (http://www.netlib.org/blas). Accelerated BLAS libraries such as ATLAS (http://math-atlas.sourceforge.net) are recommeded for better performance. 
|-
|'''LAPACK'''||Linear Algebra Package (http://www.netlib.org/lapack). 
|-
|'''PCRE'''||The Perl Compatible Regular Expression library (http://www.pcre.org). 
|-
|'''GNU Readline'''||Command-line editing library (www.gnu.org/s/readline). Readline is technically optional, but it is strongly recommended.
|}

Beyond these, there are several more optional dependencies that configure will complain about, look in the [http://www.gnu.org/software/octave/doc/interpreter/External-Packages.html manual] for the complete list.

===Run make===